Orienting, positioning, and forming nanoscale structures

ABSTRACT

A method. A first copolymer is provided. A substrate is provided having an energetically neutral surface layer with at least one trough integrally disposed thereon with sidewalls. A first film of the first copolymer is coated inside the trough. Line-forming microdomains are assembled of the first copolymer forming first self-assembled structures within the first film normal to the sidewalls and parallel to the surface layer. The first and second polymer blocks are removed from the first film and oriented structures remain in the trough normal to the sidewalls and parallel to the surface layer. A second film of a second copolymer is coated inside the trough. Line-forming microdomains are assembled of the second copolymer, and form second self-assembled structures within the second film oriented normal to the oriented structures and parallel to the sidewalls. The third and fourth polymer blocks are removed, and at least one second oriented structure remains.

FIELD OF THE INVENTION

The invention relates to methods for aligning microdomains of blockcopolymers on substrates and structures formed therefrom.

BACKGROUND OF THE INVENTION

Miniaturization is a driving force to improve device performance andreduce cost for chip manufacturing. Current lithographic techniques arebased on a “top-down” approach, wherein patterns are imaged onto aresist via optical projection through a predefined mask. However it isbecoming increasingly difficult and expensive to extend this approach tocreate patterns with dimensions on the nanometer scale. Accordingly,there exists a need for a practical and economical approach to createpatterns with dimensions on the nanometer scale.

SUMMARY OF THE INVENTION

The present invention relates to a method, comprising:

providing a first block copolymer;

providing a substrate having an energetically neutral surface layer,said surface layer having at least one trough integrally disposedthereon, said at least one trough comprising a substantially planarfirst sidewall and a substantially planar second sidewall opposite saidfirst sidewall, wherein said first sidewall and said second sidewall aresubstantially normal to said surface layer, said first and said secondsidewalls being separated by a distance corresponding to a width of abottom surface of said at least one trough;

forming a first film inside said at least one trough, said first filmcomprising said first block copolymer;

assembling line-forming microdomains of said first block copolymerwithin said first film, said microdomains of said first block copolymerforming first self-assembled structures within said first film, saidfirst self-assembled structures oriented substantially normal to saidfirst sidewall and said second sidewall and substantially parallel tosaid surface layer;

removing at least one microdomain from said first film such thatoriented structures remain in said trough, wherein said orientedstructures are oriented substantially normal to said first sidewall andsaid second sidewall and substantially parallel to said surface layer;

providing a second block copolymer;

forming a second film inside said at least one trough, said second filmcomprising said second block copolymer; and

assembling line-forming microdomains of said second block copolymerwithin said second film, said line-forming microdomains of said secondblock copolymer forming second self-assembled structures within saidsecond film, said second self-assembled structures orientedsubstantially normal to said oriented structures and substantiallyparallel to said first sidewall and said second sidewall.

The present invention relates to a structure, comprising:

a substrate having a surface layer, said surface layer configured toinduce a block copolymer to form line-forming microdomains, said surfacehaving at least one trough integrally disposed thereon, said at leastone trough comprising a substantially planar first sidewall and asubstantially planar second sidewall opposite said first sidewall,wherein said first sidewall and said second sidewall are substantiallynormal to said surface layer, said first and said second sidewalls beingseparated by a distance corresponding to a width of a bottom surface ofsaid at least one trough;

at least one oriented inorganic structure disposed inside said at leastone trough, said at least one structure oriented substantially normal tosaid first sidewall and said second sidewall and substantially normal tosaid surface layer; and

a block copolymer film disposed in said at least one trough, whereinsaid block copolymer comprises a first block comprising a first polymer,said first block being covalently bonded to a second block comprising asecond polymer to form a repeating unit of the block copolymer, saidfirst and second polymers being different, wherein line-formingmicrodomains of said block copolymer are aligned substantially parallelto said first and second sidewalls and substantially normal to said atleast one oriented inorganic structure.

The present invention relates to a method, comprising:

providing a substrate having a surface layer, said surface layerconfigured to induce a block copolymer to form line-formingmicrodomains, said surface having at least one trough integrallydisposed thereon, said at least one trough comprising a substantiallyplanar first sidewall and a substantially planar second sidewallopposite said first sidewall, wherein said first sidewall and saidsecond sidewall are substantially normal to said surface layer, saidfirst and said second sidewalls being separated by a distancecorresponding to a width of a bottom surface of said at least onetrough;

providing at least one first oriented structure disposed inside said atleast one trough, said at least one first oriented structure is orientedsubstantially normal to said first sidewall and said second sidewall andsubstantially parallel to said surface layer;

forming a film in said at least one trough, said film comprising a blockcopolymer, said block copolymer comprising line-forming microdomains ofa first polymer block and lamellar microdomains of a second polymerblock; and

removing at least one microdomain from said film such that at least onesecond oriented structure remains in said at least one trough, whereinsaid at least one second oriented structure is oriented substantiallynormal to said at least one first oriented structure and substantiallyparallel to said first sidewall and said second sidewall.

The present invention provides a practical and economical approach tocreate patterns with dimensions on the nanometer scale.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the invention are set forth in the appended claims. Theinvention itself, however, will be best understood by reference to thefollowing detailed description of illustrative embodiments when read inconjunction with the accompanying drawings.

FIG. 1 is a perspective representation of a substrate having a substratelayer and an energetically neutral surface layer integrally disposedthereon, in accordance with embodiments of the present invention.

FIG. 2 is a cross-sectional view of a section of FIG. 1, in accordancewith embodiments of the present invention.

FIG. 3 depicts a substrate having an energetically neutral surface layerand at least one trough and sidewalls, in accordance with embodiments ofthe present invention.

FIG. 4 depicts a substrate having an energetically neutral surface layerwhich may be characterized by at least one trough where an orientedstructure remains in the trough, in accordance with embodiments of thepresent invention.

FIG. 5 is an illustration of the substrate of FIG. 4 after theapplication of a second film in the trough where at least onemicrodomain has been removed from the second film, in accordance withembodiments of the present invention.

FIG. 6 is a flowchart which illustrates generalized method steps, inaccordance with embodiments of the present invention.

FIG. 7A is a scanning electron microscope (SEM) image of a structure ina trough on an energetically neutral surface layer of a substrate,formed from a film of a combination of a block copolymer and a misciblematerial, in accordance with embodiments of the present invention.

FIG. 7B is an SEM image of a structure in a trough on an energeticallyneutral surface layer of a substrate, formed from a film, where theseparation between sidewalls is greater than the separation betweensidewalls in FIG. 7A, in accordance with embodiments of the presentinvention.

FIG. 8 is an SEM image of an oriented structure 704 on an energeticallyneutral surface layer of a substrate having at least one trough, wherethe trough has the shape of an angle and the sidewalls are not parallelto each other, in accordance with the embodiments of the presentinvention.

FIG. 9 is an SEM image of a structure in a trough on an energeticallyneutral surface layer of a substrate, in accordance with embodiments ofthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

Although certain embodiments of the present invention will be shown anddescribed in detail, it should be understood that various changes andmodifications may be made without departing from the scope of theappended claims. The scope of the present invention will in no way belimited to the number of constituting components, the materials thereof,the shapes thereof, the relative arrangement thereof, etc., and aredisclosed simply as examples of embodiments. The features and advantagesof the present invention are illustrated in detail in the accompanyingdrawings, wherein like reference numerals refer to like elementsthroughout the drawings. Although the drawings are intended toillustrate the present invention, the drawings are not necessarily drawnto scale.

The following are definitions:

A monomer as used herein is a molecule that can undergo polymerizationthereby contributing constitutional units to the essential structure ofa macromolecule, an oligomer, a block, a chain, and the like.

A polymer as used herein is a macromolecule comprising multiplerepeating smaller units or molecules (monomers) derived, actually orconceptually, from smaller units or molecules, bonded togethercovalently or otherwise. The polymer may be natural or synthetic.

A copolymer as used herein is a polymer derived from more than onespecies of monomer.

A block copolymer as used herein is a copolymer that comprises more thanone species of monomer, wherein the monomers are present in blocks. Eachblock of the monomer comprises repeating sequences of the monomer. Aformula (1) representative of a block copolymer is shown below:

-(A)_(a)-(B)_(b)—(C)_(c)-(D)_(d)-  (1)

wherein A, B, C, and D represent monomer units and the subscripts “a”,“b”, “c”, and “d”, represent the number of repeating units of A, B, C,and D respectively. The above referenced representative formula is notmeant to limit the structure of the block copolymer used in anembodiment of the present invention. The aforementioned monomers of thecopolymer may be used individually and in combinations thereof inaccordance with the method of the present invention.

A di-block copolymer has blocks of two different polymers. A formula (2)representative of a di-block copolymer is shown below:

-(A)_(m)-(B)_(n)-  (2)

where subscripts “m” and “n” represent the number of repeating units ofA and B, respectively. The notation for a di-block copolymer may beabbreviated as A-b-B, where A represents the polymer of the first block,B represents the polymer of the second block, and -b- denotes that it isa di-block copolymer of blocks of A and B. For example, PS-b-PEOrepresents a di-block copolymer of polystyrene (PS) and poly(ethyleneoxide) (PEO).

A crosslinkable polymer as used herein is a polymer having a smallregion in the polymer from which at least one polymer chain may emanate,and may be formed by reactions involving sites or groups on existingpolymers or may be formed by interactions between existing polymers. Thesmall region may be an atom, a group of atoms, or a number of branchpoints connected by bonds, groups of atoms, or polymer chains.Typically, a crosslink is a covalent structure but the term is also usedto describe sites of weaker chemical interactions, portions ofcrystallites, and even physical interactions such as phase separationand entanglements.

Morphology as used herein describes a form, a shape, a structure, andthe like of a substance, a material, and the like as well as otherphysical and chemical properties (e.g., Young's Modulus, dielectricconstant, etc. as described infra).

Amphiphilic as used herein is used to describe a molecule and amacromolecule that is or has in part both polar and non-polar portionsthat constitute the molecule and the macromolecule.

Thermosetting polymer as used herein is a polymer or a prepolymer in asoft solid or viscous state that changes irreversibly into an infusible,insoluble polymer network by curing. Typically, curing can be by theaction of heat or radiation causing the production of heat, or both.Further, curing can be by the action of heat and/or radiation thatproduces heat resulting in the generation of a catalyst which serves toinitiate crosslinking in the region of exposure.

Photosetting polymer as used herein is a polymer or a prepolymer in asoft solid or viscous state that changes irreversibly into an infusible,insoluble polymer network by curing. Typically, curing can be by theaction of exposing the polymer or prepolymer to light (UV, IR, visible,etc). Further, curing can be by the action of exposure to radiationresulting in the generation of a catalyst which serves to initiatecrosslinking in the region of exposure.

Nanostructure as used herein is a structure on the order of 1 nanometer(nm) to 100 nm in dimension. Examples of the structure may include butare not limited to nanorods, nanosheets, nanospheres, nanocylinders,nanocubes, nanoparticles, nanograins, nanofilaments, nanolamellae, andthe like having solid composition and a minimal structural dimension ina range from about 1 nm to about 100 nm. Further examples of thestructure may include but are not limited to spherical nanopores,cylindrical nanopores, nanotrenches, nanotunnels, nanovoids, and thelike having their void or shape defined by the material or matrix thatsurrounds them and having a diameter in a range from about 1 nm to about100 nm.

A substrate, as used herein, is a physical body (e.g., a layer or alaminate, a material, and the like) onto which a polymer or polymericmaterial may be deposited or adhered. A substrate may include materialsof the Group I, II, III, and IV elements; plastic material; silicondioxide, glass, fused silica, mica, ceramic, metals deposited on theaforementioned substrates, combinations thereof, and the like.

An energetically neutral surface layer, as used herein, is a surfacelayer whose chemical and morphological composition affords substantiallyno preferential or selective affinity for either polymer block in ablock copolymer or an associated functional group or moiety, such asthrough ionic bonds, dipole-dipole forces, hydrogen bonding, and similarintermolecular forces.

FIG. 1 is a perspective representation of a substrate 100 having asubstrate layer 101 and an energetically neutral surface layer 105integrally disposed thereon. The surface layer 105 may be characterizedby at least one trough 102, having a first sidewall 103 and a secondsidewall 104 separated by a bottom surface 106 of the trough 102. Thesurface layer 105 may be characterized by a single trough 102 or aplurality of troughs. The sidewalls 103 and 104 may be substantiallyparallel to each other. The sidewalls 103 and 104 may be substantiallynormal to the surface layer 105. The at least one trough 102 may have ashape of a line, an arc, an angle, a combination thereof, and the like.

FIG. 2 is a cross-sectional view of a section of FIG. 1 through plane106. FIG. 2 shows an embodiment where sidewall 103 and sidewall 104 oftrough 102 may have a height of 202 and be separated by a distance 201.The height 202 of sidewall 103 and 104 may be about 30 nanometers (nm)to about 200 nm, and separated by a distance 201 of about 20 nm to about2000 nm.

These examples are not meant to limit the shape, size, or orientation ofthe topography of the surface layer 105. For example, the sidewall 103and sidewall 104 may have different heights.

FIG. 3 depicts an embodiment of the present invention with a substrate100 having an energetically neutral surface layer 105 and at least onetrough 102 and sidewalls 103 and 104. The trough may be coated with afilm 300 of a block copolymer. The energetically neutral surface mayinduce the lamellae-forming block copolymer to align perpendicularlywith respect to the substrate interfaces. Lamellae of the polymer blocks302 and 305 of the block copolymer within the film may self-assemble andbe induced to align with respect to the sidewalls 103 and 104, due tothe high rigidity of one of the polymer block (302 or 305) and the longpersistence length of the block copolymer microdomains. Self-assembledstructures (nanostructures) of the first polymer block 305 andself-assembled structures (nanostructures) of the second polymer block302, formed from aligned microdomains of aligned lamellae, may beoriented substantially normal to sidewalls 103 and 104 and substantiallyparallel to the surface layer 105. The same alignment principle may beapplicable for line-forming morphology in the case of parallelcylinders. For example, with a trough with energetically neutralsidewalls and a preferentially wetted substrate, cylinder forming blockcopolymers may be used to generate lines which align perpendicularly tothe trough sidewalls.

For example, rod-coil block copolymers such aspolyhexylisocyanate-b-polystyrene andpoly(phenylquinoline)-b-polystyene, may be used to form films where thehigh stiffness of one domain of these block copolymers will induce theline-forming structures to align substantially normal to the sidewallsof the trough and substantially parallel to the surface layer.

The rigidity of a particular polymer block (and microdomains thereof) inthe block copolymer may be controlled by combining the block copolymerwith a third material which is miscible with that particular block ofthe copolymer, where the miscible material may perform as a stiffeningcompound and increase the rigidity of that polymer block. The rigidityor stiffness of the microdomains of the polymer block may be controlledby using a different miscible material. Organic homopolymers, inorganichomopolymers, inorganic precursors, inorganic oligomers, crosslinkablehomopolymers, or a combination of these may be used as the misciblematerial. The structure formed by the alignment of the line-formingmicrodomains of the block copolymer may be frozen when a crosslinkablematerial is used.

The morphology of the microdomains is determined by the Flory-Hugginsinteraction parameter between polymers A and B, molecular weight, andthe volume fraction of A (or B). For a given block copolymer system,volume fraction may be the main parameter to determine the morphology.For example, for a di-block copolymer A-b-B, in general, when thepolymer chain length of A is approximately the same as the polymer chainlength of B, the di-block copolymer may form line-forming microdomains.The combined volumetric fraction of the first polymer block, A, and themiscible material with respect to the di-block copolymer may be in arange from about 0.2 to about 0.8. For block copolymers used in thepresent invention without a miscible material, the mole fraction of theminority block in the block copolymer may be about 0.2 to about 0.5.

After the film is formed, at least one microdomain may be removed fromthe film, leaving an oriented structure remaining in the trough.Processes that may be used may include thermolysis, UV/ozone processing,supercritical CO₂ processing, solvent extraction, a dry etching process,reactive ion etching, a wet etching process, and the like, and may beused individually and/or in combinations thereof in accordance withmethods of the present invention. Removing at least one microdomain maycomprise removing at least one domain from one or more polymer blocks ofthe block copolymer. For example, in the case of a di-block copolymer,the first polymer block, the second polymer block, or both may beremoved.

If a miscible material is combined with the block copolymer, the blockcopolymer may be removed to leave an oriented structure in the trough.For example, in the case of a di-block copolymer, if the misciblematerial, which is selectively miscible with the first block of theblock-copolymer, is an inorganic precursor, the film and substrate maybe heated between about 350° C. and about 600° C. to remove all organicpolymers from the film. The remaining material may form an orientedstructure in the trough, since it may have been preferentially locatedin the microdomains of the first polymer block prior to the removal ofthe di-block copolymer. The remaining inorganic oriented structure mayhave substantially the same orientation as the associated self-assembledstructures in which the miscible material was mixed, where the remainingstructure may be substantially normal to the sidewalls, andsubstantially parallel to the surface layer. In an embodiment of thepresent invention, the remaining structure may be a nanostructure.

FIG. 4 depicts a substrate 100 having an energetically neutral surfacelayer 105 which may be characterized by at least one trough, whereuponan oriented structure 402, derived from 305 in FIG. 3, remains in thetrough after the removal of at least one microdomain from the film. Thestructure 402 may be oriented substantially normal to sidewalls 103 and104 and substantially parallel to the surface layer 105.

After the removal of at least one microdomain from the first film, asecond film of a second combination, formed from a second blockcopolymer, may be applied in the trough on the energetically neutralsurface, in a similar manner to the first film. The second film maysubstantially cover the first oriented structure in the trough and fillgaps between sections from where at least one microdomain of the firstfilm has been removed. The microdomains of the second block copolymermay assemble in the second film to form self-assembled structures whichmay be oriented substantially normal to the first oriented structureformed after the application of the first film, where the first orientedstructure provides a guiding topography for the self-assembledstructures of the second film. At least one microdomain of the secondfilm may be removed to leave a second oriented structure remaining inthe trough, where the second structure may be oriented substantiallyparallel to the sidewalls of the trough and substantially normal to thefirst oriented structure.

FIG. 5 is an illustration of the substrate 100 of FIG. 4 after theapplication of a second film in the trough 102 of a second blockcopolymer, where at least one microdomain from the second film has beenremoved to leave a second oriented structure 410 in the trough 102. Thesecond oriented structure 410 may be oriented substantially normal tothe first oriented structure 402 and substantially parallel to the firstsidewall 103 and the second sidewall 104.

FIG. 6 is a flowchart which illustrates generalized method steps 501 to511 for an embodiment of the present invention. Step 501 provides asubstrate with an energetically neutral surface layer having at leastone trough such as in FIG. 1 and FIG. 2. Step 502 provides a first blockcopolymer. Step 504 forms a first film in the trough, alignsline-forming microdomains of the first block copolymer and formsself-assembled structures, such as illustrated in FIG. 3. The first filmmay comprise the first block copolymer or a combination of the firstblock copolymer with a first miscible material, wherein the firstmiscible material acts as a stiffening compound and increases therigidity of one of the blocks of the first block copolymer in which themiscible material is preferentially miscible. Step 505 removes at leastone microdomain from the first film, resulting in first orientedstructures remain in the trough as in step 506. The oriented structuresmay, for example, resemble the structures 402 of FIG. 4, where thestructures 402 are substantially parallel to the sidewalls 103 and 104and are substantially parallel to the surface layer 105.

Step 507 provides a second block copolymer. The second block copolymermay be different from the first block copolymer. In step 509, a secondfilm is formed in the trough, after which line-forming microdomains ofthe second block copolymer are aligned to form self-assembled structuresin the film. In step 510, at least one microdomain of the second blockcopolymer is removed from the second film, resulting in second orientedstructure remains in the trough, as in 511, where the second orientedstructure remaining in 511 may be aligned substantially normal to thefirst oriented structure, and substantially parallel to the surfacelayer. As above, the second film may comprise the second block copolymeror a combination of the second block copolymer combined with a secondmiscible material, where the second miscible material may bepreferentially miscible with one block of the second block copolymer,and may act as a stiffening compound and increase the rigidity of thatblock.

EXAMPLES

FIG. 7A is a scanning electron microscope (SEM) image of a structure 604in a trough 610 on an energetically neutral surface layer 600 of asubstrate, formed from a film of a combination of an amphiphilicdi-block copolymer, polystyrene-block-poly(ethylene oxide) (hereinreferred to as PS-b-PEO) and a miscible material,poly(methylsilsesquioxane), hereafter referred to as PMSSQ. The PS-b-PEOcomprised a first block of a first polymer, PEO, and a second block of asecond polymer, PS, where the molecular weight of the PS block was about19,000 grams/mole (g/mol), and the molecular weight of the PEO block wasabout 12,000 g/mol. The composition of the PS-b-PEO may vary in theamount of PS block and PEO block present in the PS-b-PEO di-blockcopolymer, where the molecular weight of each block of the di-blockcopolymer may be in a range from about 2,000 g/mol to about 100,000g/mol. The total molecular weight of block copolymers in the presentinvention may range from about 10,000 g/mol to about 200,000 g/mol. Thefractions of the monomer blocks present can be represented in percentmillimoles (% mmol.), percent by weight (wt. %), volume fraction, andthe like. The combined volumetric fraction of the PEO+PMSSQ blockpresent in the combination was about 0.65. The PMSSQ provided ispreferentially miscible with the PEO block of PS-b-PEO over the PS, andmay act as a stiffening compound to increase the stiffness or rigidityof the PEO block in the di-block copolymer and the PEO microdomains inthe formed film.

The combination of PS-b-PEO and PMSSQ was spin coated into the trough610 on the substrate having an energetically neutral surface layer 600,at a spin speed of about 3,000 rotations per minute (rpm). The PMSSQ,which is miscible with PEO and immiscible with PS, may reside in or nextto PEO microdomains. The volume fraction of PEO+PMSSQ phase, which isdetermined by the chain length of each block of the di-block copolymerand combination composition, may determine the morphology of thecombinations. Horizontal light lines 604 in the image are the remainingaligned inorganic structure after organic polymer has been removed byheating the film to 450° C. Dark horizontal lines 603 in FIG. 6A aregaps formed where the PS lamellar microdomains of the organic di-blockcopolymer were removed. Since the PMSSQ is selectively miscible in thePEO microdomains relative to the PS microdomains, removal of the PSmicrodomains leaves a space or gap. As seen in the images, the orderedstructure 604 remaining in the trough 610 is oriented substantiallynormal to the sidewalls 601 and 602 of the trough 610 and substantiallyparallel to the surface layer 600.

FIG. 7B is an SEM image of a structure 607 in a trough 611 on anenergetically neutral surface layer 609 of a substrate, formed from afilm of a combination of PS-b-PEO and PMSSQ, prepared in a similarfashion as the sample shown in FIG. 7A, where the separation betweensidewalls 605 and 606 in FIG. 7B is greater than the separation betweensidewalls 602 and 601 in FIG. 7A. Horizontal light lines 607 in theimage are the remaining aligned inorganic structure after organicpolymer has been removed by heating the film to 450° C. Dark horizontallines 608 in FIG. 7B are gaps formed where the PS lamellar microdomainsof the organic di-block copolymer were removed by heating the sample to450° C. Since the PMSSQ is selectively miscible in the PEO microdomainsrelative to the PS microdomains, removal of the PS microdomains leaves aspace or gap. As seen in the images, the ordered structure 607 remainingin the trough 611 is oriented substantially normal to the sidewalls 605and 606 of the trough 611 and substantially parallel to the surfacelayer 609.

FIG. 8 is an SEM image of an oriented structure 704, prepared in asimilar manner to those shown in FIG. 7A and FIG. 7B, on anenergetically neutral surface layer 700 of a substrate having at leastone trough 705, formed from a film of a combination of PS-b-PEO andPMSSQ, where the trough 705 has the shape of an angle and the sidewalls701 and 702 are not parallel to each other. Light lines 704 are theoriented structure remaining in the trough 705 after removal of organicpolymer by heating the sample to 450° C. Dark lines 703 are gaps betweenthe remaining structures where organic polymer has been removed. Theoriented structure 704 is substantially normal to the sidewalls 701 and702, and substantially parallel to the surface layer 700.

FIG. 9 is an SEM image of a structure 904 and 905 in a trough 906 on anenergetically neutral surface layer 900 of a substrate. The structure904 was prepared as described above by spin coating (30 seconds @ 3000rpm) a combination of PS-b-PEO and PMSSQ to form a first film in thetrough 906, followed by heating to 450° C. to remove organic material,where the first oriented inorganic structure 904 remained in the trough.The first oriented structure 904 is oriented substantially perpendicularto sidewalls 901 and 902. A second film of a second combination ofPS-b-PEOP with PMSSQ was then formed in the trough 906 by spin coatingas above, followed by heating to 450° C. to remove organic material toleave a second oriented structure 905 remaining in the trough 906. Thesecond oriented structure 905 is substantially perpendicular to thefirst oriented structure 904 and substantially parallel to the sidewalls901 and 902. Dark spaces 903 are gaps formed where the PS lamellarmicrodomains of the organic di-block copolymer were removed.

The trough on an energetically neutral surface layer may be preparedusing electron beam (e-beam) lithography. The use of e-beam lithographyis not meant to limit the technique that can be used to create a troughin the surface layer. Alternative processes may include but are notlimited to chemical vapor deposition (CVD), plasma deposition,stereolithography, photolithography, sputtering, nanoimprinting, and anyother means for creating a trough in a surface layer. A trough in asurface layer may be made energetically neutral by the deposition of athin film of appropriate chemical composition. In addition, the troughin the surface layer may not necessarily be integrally disposed upon thesubstrate layer and may be created by the deposition or layering ofadditional material on the surface layer in a pattern to create atrough.

The use of PS-b-PEO as the di-block copolymer is not meant to limit thetype of the di-block copolymer that may be used in embodiments of thepresent invention. The di-block copolymer may be but is not limited toan amphiphilic organic di-block copolymer, an amphiphilic inorganicdi-block copolymer, a combination thereof, and the like. Specificexamples of a first polymer of a di-block copolymer may include but arenot limited to poly(ethylene oxide), poly(propylene glycol),poly(alkylene oxides), poly(acrylic acids), poly(methacrylic acid),poly(dimethylamino ethylmethacrylate), poly(hydroxyalkyl methacrylates),poly(alkyleneoxide acrylates), poly(alkyleneoxide methacrylates),poly(hydroxyl styrenes), polycarbohydrates, poly(vinyl alcohols),poly(ethylene imines), polyoxazolines, polypeptides, poly(vinylpyridines), polyacrylamides, poly(methyl vinyl ethers), poly(vinylcarboxylic acid amides), polymethylmethacrylate,poly(N,N-dimethylacrylamides), combinations thereof, and the like.Specific examples of a second polymer of a di-block copolymer mayinclude but are not limited to polystyrene, poly(α-methyl styrene),polynorbornene, polylactones, polylactides, polybutadiene, polyisoprene,polyolefins, polymethacrylates, polysiloxanes, poly(alkyl acrylates),poly(alkyl methacryaltes), polyacrylonitriles, polycarbonates,poly(vinyl acetates), poly(vinyl carbonates), and polyisobutylenes,combinations thereof, and the like. Di-block copolymers formed from theaforementioned first and second polymers may be used individually and incombinations thereof in accordance with the method of the presentinvention.

The use of PMSSQ as a miscible material in this example is not meant tolimit the type of the crosslinkable material that may be used in anembodiment of the present invention. Other materials that may be usedinclude but are not limited to inorganic precursors, organichomopolymers, crosslinkable homopolymers, combinations thereof, and thelike. The inorganic precursor may be silsesquioxane having the formula(RSiO_(1.5))_(n), wherein R may be a hydrido group or an alkyl grouphaving 1 to 3 carbon atoms, wherein n may be in a range from about 10 toabout 500, and wherein the crosslinkable homopolymer may have amolecular weight in a range from about 600 g/mol to about 30,000 g/mol.Crosslinkable homopolymers may include organic crosslinkable polymers;inorganic crosslinkable polymers; inorganic precursors, thermosettingcrosslinkable polymers such as epoxy resins, phenolic resins, aminoresins, bis-maleimide resins, dicyanate resins, allyl resins,unsaturated polyester resins, polyamides, and the like; photosettingcrosslinkable polymers; polysilanes; polygermanes; carbosilanes;borazoles; carboranes; amorphous silicon carbides; carbon doped oxides;and the like. The aforementioned crosslinkable polymers may be usedindividually and in combinations thereof in accordance with the methodof the present invention.

The combination of the block copolymer and the miscible material may beformed in a solvent solution and cast as a solution, which may requiresolvent removal for complete film formation. A thin film of thecombination may be spin coated onto a substrate, where a spin speed maybe in a range from about 1 rpm to about 5,000 rpm. The combination maybe spin coated at room temperature without a post-drying process.Alternatively, a film sample on a substrate may be thermally annealed,after forming the film, at a temperature of about 100° C. for about 10hours, for example. Also, a film sample on a substrate may be vaporannealed, after forming the film on the substrate, by annealing theadhering film under organic solvent vapor at room temperature (about 25°C.) from about 10 hours to about 15 hours, for example. Lamellarmicrodomains may assemble during or after film formation in the trough.Likewise, formation of the associated self-assembled structures mayoccur during formation of the block copolymer film or after the film hasbeen formed and the energetically neutral surface.

The spin coating process used is not meant to limit the type ofprocesses that may be used when forming a film in an embodiment of thepresent invention. Other processes such as chemical vapor deposition(CVD), photochemical irradiation, thermolysis, spray coating, dipcoating, doctor blading, and the like may be used individually and incombinations thereof in accordance with the method of the presentinvention.

The formation of the self-assembled structures of line-formingmicrodomains such as lamellar microdomains and cylindrical microdomainsmay be accomplished by forming the film on the substrate throughspin-casting, dip-coating and spray-coating, thermal annealing afterforming the film on the substrate, vapor annealing after forming saidfilm on the substrate, a combination thereof, or any other process whichprovides a means for forming the structures.

The foregoing description of the embodiments of this invention has beenpresented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formdisclosed, and obviously, many modifications and variations arepossible. For example, the miscible material may be selected to bepreferentially miscible with the second block of the block copolymer.Such modifications and variations that may be apparent to a personskilled in the art are intended to be included within the scope of thisinvention as defined by the accompanying claims.

1. A method, comprising: providing a first di-block copolymer comprisinga first block of a first polymer, said first block being covalentlybonded to a second block of a second polymer to form a repeating unit ofsaid first block copolymer, said first polymer comprisingpoly(methacrylic acid), said second polymer comprising polybutadiene;providing a substrate having an energetically neutral surface layer,said surface layer having at least one trough integrally disposedthereon, said at least one trough comprising a substantially planarfirst sidewall and a substantially planar second sidewall opposite saidfirst sidewall, wherein said first sidewall and said second sidewall aresubstantially normal to said surface layer, said first and said secondsidewalls being separated by a distance corresponding to a width of abottom surface of said at least one trough, said at least one troughhaving a shape of an angle; dip coating a first film inside said atleast one trough, said first film comprising said first di-blockcopolymer and a first miscible material, wherein said first misciblematerial is miscible with said first di-block copolymer, said firstmiscible material comprising a crosslinkable homopolymer having aformula (RSiO_(1.5))_(n), wherein R is selected from the groupconsisting of a hydrido group and an alkyl group having 1 to 3 carbonatoms, wherein n is in a range from about 10 to about 500, and whereinsaid crosslinkable homopolymer has a molecular weight in a range fromabout 600 grams/mole (g/mol) to about 30,000 g/mol; assemblingline-forming microdomains of said first di-block copolymer within saidfirst film, said microdomains of said first di-block copolymer formingfirst self assembled structures within said first film, said firstself-assembled structures oriented substantially normal to said firstsidewall and said second sidewall and substantially parallel to saidsurface layer, presence of said first miscible material within saidfirst di-block copolymer inducing said line-forming microdomains of saidfirst di-block copolymer to align with respect to said first sidewalland said second sidewall after said first film is formed inside said atleast one trough, said first miscible material increasing rigidity ofsaid line-forming microdomains of said first block of said firstpolymer; removing said first polymer block and said second polymer blockfrom said first film by heating said film to a temperature between about350° C. and about 600° C., such that first oriented structures remain insaid trough, wherein said first oriented structures are orientedsubstantially normal to said first sidewall and said second sidewall andsubstantially parallel to said surface layer; providing a seconddi-block copolymer comprising a first block of a third polymer, saidfirst block of said third polymer being covalently bonded to a secondblock of a fourth polymer to form a repeating unit of said second blockcopolymer, said third polymer comprising poly(propylene glycol), saidfourth polymer comprising polynorbornene, said first polymer differentfrom said third polymer, said second polymer different from said fourthpolymer; spray coating a second film inside said at least one trough,said second film comprising said second di-block copolymer and a secondmiscible material, wherein said second miscible material is misciblewith said second block copolymer, said second miscible materialcomprising a crosslinkable homopolymer having a formula(RSiO_(1.5))_(n), wherein R is selected from the group consisting of ahydrido group and alkyl group having 1 to 3 carbon atoms, wherein n isin a range from about 10 to about 500, and wherein said crosslinkablehomopolymer has a molecular weight in a range from about 600 grams/mole(g/mol) to about 30,000 g/mol; and assembling line-forming microdomainsof said second di-block copolymer within said second film, saidline-forming microdomains of said second di-block copolymer formingsecond self assembled structures within said second film, said secondself-assembled structures oriented substantially normal to said firstoriented structures and substantially parallel to said first sidewalland said second sidewall, presence of said second miscible materialwithin said second di-block copolymer inducing said line-formingmicrodomains of said second di-block copolymer to align with respect tosaid first oriented structures after said second film is formed insidesaid at least one trough, said second miscible material increaserigidity of said line-forming microdomains of said first block of saidthird polymer; and removing said third polymer block and said fourthpolymer block from said film by heating said film to a temperaturebetween about 350° C. and about 600° C., such that at least one secondoriented structure remains in said at least one trough, wherein said atleast one second oriented structure is oriented substantially normal tosaid at least one first oriented structure and substantially parallel tosaid first sidewall and said second sidewall. 2-20. (canceled)